rear heated screen

Hi all , in the finishing stages of my rebuild and starting to go through my snagging list and my rear heated screen doesn't work, its a 200tdi 110 its had a complete new loom and the instrument pack has been upgraded to the td5 clocks and warning light panel , I've put a new relay in and its got a new switch,. Have got 14 volts at the switch and when on 14 volts coming off the other 2 pins but no power at the heated screen but the rear wash wipe works. So any ideas ?
Is relay YWB10027 the correct relay ? And I've upgraded the switch to the later YUF101500 which was an OEM one but is it wired the same as the original ? Am at a loss any ideas welcome.
cheers Ian

I'm not great with electrical stuff, so I have to try and do things as systematically as I can. Can you access the relay to check 14v there? How many cable options do you have at the loom at the rear of the vehicle?

Yes I'll pop the binnacle off and check that , just trying to fit my door cards not going to plan then does anything. Just the white black spare which is on the loom going into the door all other wires fit to rear wash wipe and that works , just put a multimeter on the white/black wire in the engine bay were it plugs into the chassis loom and no power there so must be behind the dash and tried old switch and still doesn't work so switch ok, so will try and get the relay out .
Cheers Ian

Ian Maycock said:

Yes I'll pop the binnacle off and check that , just trying to fit my door cards not going to plan then does anything. Just the white black spare which is on the loom going into the door all other wires fit to rear wash wipe and that works , just put a multimeter on the white/black wire in the engine bay were it plugs into the chassis loom and no power there so must be behind the dash and tried old switch and still doesn't work so switch ok, so will try and get the relay out .
Cheers Ian

Click to expand...

For me, things rarely go to plan and often take three times longer than expected. sometimes even longer

Al2O3 said:

For me, things rarely go to plan and often take three times longer than expected. sometimes even longer

Click to expand...

Think that's most people
Also if you get power to it and it still doesn't work the element in the glass may be broken

Yep glad its not just me , am fitting some la salle ones to front and 2nd row and a bolt on bits rear door card did rear one took a bit of fettling to door lock but done so tried drivers side 2nd row door spent ages faffing around couldn't get it to go on. Threw a wobbler dog went off and hid so left that and thought try the front one 1/2 hr it was all fitted and done so locked up and come in for a brew, try again tomorrow . Got no power coming out of the cab so it must be something to do with the relay , it threw me cus everything is brand new including the loom so looks like dash out again . I'll get there one day.
cheers Ian

It's not unknown for new relays to be faulty, I'd get the meter or test lamp out. You've got power to it, can you hear it click when you operate the switch? If so, the next point to test at is the connector where the rear loom plugs in.

Right finished fitting all my door cards so had a look at this problem ,right tried another new relay still no good that's 3 tried now so got multi meter out and with engine running this is the result ,pin 30 brown wire 14v all the time , pin 86 white/green 14v when switch is on, pine 85 black/pink 14v when switch is on , pin 87 white/green and brown/white 0v all the time . Is this how the relay should work ? is the black/pink wire causing the problem ? were does that wire go too ?
any help much appreciated as always >
cheers Ian

Please note!
There is a lack of pictures with this thread

Is this the relay?

I'm no sparky but, I'd say what you are getting is almost correct, pin 30 should be live with 14v waiting to be connected to pin 87 when the relay is switched on. When you switch on wiper it goes live across 85 and 86 as you have found. This should switch on the heavier side of the relay and you should then get 14v from pin 87 to earth too. Unless, your wiper isn't earthed and then nothing will flow through 30 to 87 cos it has to have somewhere to go. which should be through the motor and then through an earth on the body and back to the battery.
If this is wrong, someone will soon amend.

Ye the original relay looked like that the new ones were black , I think you've got a bit confused there its the rear heated screen that doesn't work but think I understand what you mean. Its all working as it should but if the earth on the rear heated screen itself is no good the relay won't switch over and the power won't get to the screen , is my thinking correct ? The earth for the rear screen is a short wire from the top of the screen to the rear door.
cheers Ian

Ian Maycock said:

Ye the original relay looked like that the new ones were black , I think you've got a bit confused there its the rear heated screen that doesn't work but think I understand what you mean. Its all working as it should but if the earth on the rear heated screen itself is no good the relay won't switch over and the power won't get to the screen , is my thinking correct ? The earth for the rear screen is a short wire from the top of the screen to the rear door.
cheers Ian

Click to expand...

Sorry, don't know how I changed that to rear wiper
The switching side of your relay should switch no matter what (so long as it's not broken) This closes the circuit in the higher current side of the relay which is providing power to your heated screen element. However, all it is doing is closing, what it thinks, is the only gap in the circuit. If the rest of the circuit is not complete ie the heater element is not connected to earth the current will not get to the element. You should get +14v at pin 67 if you test with your meter from pin 67 to a good earth. EDIT When the relay is switched on that is!